Backup

sekai --store ./sekai-store backup ./world

Records the current world state as a new snapshot and prints the snapshot id, chunk/blob counts, tombstones, skipped regions, and carried chunks.

• --with-diff additionally derives volatile diff views alongside blobs (slower ingest; the hot path stays decode-free without it).
• --jobs N sets the ingest worker count (0 means one per CPU).
• --progress shows a stderr progress bar (refused with --json).
• Scope flags (--in, --region, --kind) restrict what is recorded; see Scope selection.
• For a dry-run preview of the above, see status under Inspection.
• When the store directory is created by the backup, the CLI says so on stderr (human output only).

Unchanged regions are skipped by fingerprint; unchanged chunks inside changed regions resolve through fallback and cost no new blobs. A backup with no changes still writes one snapshot row.